That may be possible. It’s a good idea. Hopefully I can do that eventually.
It is most important that you understand to purge air first. The charge on
these systems is not as sensitive as many make it out to seem. Especially
if you have a capillarity tube type restrictive device at the evap coil.
The refrigerant is only allowed to be metered to the evap coil at fixed
rate if a bit more freon there remainder is held in the pot of the
compressor. No big deal as long as it is not overly excessive.

I have a brand new manifold that has a bad high side gauge. When I purge my
manifold, I purge from my yellow hose. It has a low leak fitting, and a
schrader T that it can be looped on, so I use an allen wrench to open the
low loss core, and blow the air out. That way, when I put the open end back
on the T, it keeps air from entering.

I have a brand new manifold that has a bad high side gauge. When I purge my
manifold, I purge from my yellow hose. It has a low leak fitting, and a
schrader T that it can be looped on, so I use an allen wrench to open the
low loss core, and blow the air out. That way, when I put the open end back
on the T, it keeps air from entering. Also, my high side hose has a low
loss, so I remove the low loss, and release the liquid back into the low
side before I remove my hoses.

Sometimes new construction homes will be undercharged, due to a longer line
set to the evaporator. The installers fail to test the refrigerant for the
correct amount, therefore adding extra refrigerant is common.

In Canada we have to scale or weigh in our charge. If I found a unit with
30 psi on the low side and It was over 100 degrees out, that would be a
sure indication that system had a leak. I would by law have to repair the
leak or recover the R22 in the unit and decommission the unit for
environmental purposes.

I guess this is ok for topping off a system just to get the custom out of
trouble but this is NOT an ACCURATE charging method. To accurately recharge
or top off a system with a fixed metering device you would need a sling
psychrometer (for taking the wet bulb temp close to the return grilled), a
dual probe digital thermometer (1 probe for taking the temp of the suction
line & 1 probe for taking the ambient dry bulb temp), an accurate set of
gauges, & a charging chart for the refrigerant being introduced. The
charging chart determines what the superheat or
(Split) should be. Not a predetermined # in someones head as demonstrated
in this video. A digital scale is always a good idea so you know exactly
how much refrigerant to charge the custom for.﻿

I forgot to mention that if a system has a leak then its always best to
perform a leak search, find the leak, repair it, evacuate the system & then
recharge it! That is of course if the cust is willing to pay for it. I
couldnt help noticing this appears to be an old Goldman unit with a
newer.compressor in it. So, which is more? The leak repair or the
compressor replacements?﻿

I have a Payne 4 ton, on our first day of hot weather I turned the a/c on,
after 10 minutes no cooling I went outside, the fan was off and the unit
was making a hum. Took off a side plate and the capacitor top was not
flat, I changed it, unit started working properly, a couple weeks passed,
noticed cooling was barely working, bought a set of gauges and the low side
was 27 psig, I added a little over 5lbs of R-22 and the low side went to
64 psig 40 on the R–22 gage, the pipe started sweating and the inside
temp dropped and the unit cycled off and on. I noticed a oily substance
around the high side port, and on the bottom of the port dirt had
collected. I think when I changed the capacitor I took the caps off both
ports to look at them and failed to tighten the high side port causing it
to leak out freon. I will put the gauges on again in about a week to see
if it’s holding.﻿

Why do these guys continue to show potentially dangerous procedures and
then say you have to be EPA certified. Do they want average homeowner to
pay a 25000.00 fine or what lol. Heck they should fine them. This is
dangerous in my opinion. Gives the homeowner a false sense of confidence.﻿